Scraper-chain conveyors are widespread in underground mining and are used mainly as face conveyors and transfer conveyors. The former type of conveyor is disposed along a mineral face to collect the mineral product detached with cutting machines while the latter is used to transfer the product along a roadway providing access to the longitudinal gallery with the mineral face. Because of the high power consumption of scraper-chain conveyors used in the mineral face operations it is usual to provide driving assemblies at both ends of the conveyor and forming a main drive and an auxiliary drive station for the face conveyor. In both cases double drives can be used with each station possessing two drive assemblies mounted on opposite side walls of a machine frame of the drive station. It is also known to connect the face conveyor to a transfer or haulage conveyor connected downstream in the conveying direction at right angles to the face conveyor with a transfer station in the form of a movable structural unit. In this case the two conveyors are connected by a so-called cross frame on which the transfer of product from the face conveyor to the haulage conveyor is performed. U.S. Pat. No. 4,673,079 shows such a transfer station. On the cross frame forming the transfer station the drive for the face conveyor is mounted as well as the generally driveless reversal for the haulage conveyor.
Known scraper-chain conveyors take a variety of forms but all are composed of a scraper-chain assembly circulated above and below the floor plates of a series of pans connected end-to-end. The scraper-chain assemblies can have a single chain or double chain inboard scraper-chain assembly or a double chain outboard assembly. Such conveyors can also serve to guide extraction machines, such as a coal plough or a roller or chain cutting machine.
It is generally desirable to have the extraction machine driven as close as possible to the end of the face conveyor in the region of the machine frame forming the drive or transfer station, in order to be able to extract mineral or coal over the entire length of the face. In this case the conveyor drive arranged on the drive station should not hinder the movement of the extraction machine. The driving assemblies for the face conveyor are as a rule mounted on the side walls of the machine frame forming the drive or transfer station. In order to ensure that a conveyor drive mounted on the workface-side of the machine frame does not hinder the movement of the extraction machine it is known to arrange the drive transmission and motor at a distance from the frame. Between one of the side walls of the frame and the drive a spacer comprising an intermediate box or the like is arranged which is securely connected to the side wall of the frame. UK patent specification 2030100 describes such structure.
In scraper-chain conveyors the scraper-chain assembly runs around a chain drum mounted in roller bearings in the frame of the drive station. The drum provided with one or more chain wheels, represents a component which is subject to high wear and therefore the drums have to be replaced from time to time during operation. This causes problems in the cramped underground workings and means that the drive assemblies of the conveyor drive have to be mostly detached and removed from the frame. In a driveless return of a scraper-chain conveyor it is known to mount the return drum in the frame so that it can be installed and removed as an assembly unit--see DE 42 04 381 A1--. In this case, the chain drum is supported between two axial pins arranged on the machine frame or its side walls and coupled detachably therewith by screws, so that the drum can be removed after loosening the screws towards the open end of the frame and on assembly can be installed into the frame from this end.
Furthermore, it is known to mount the chain drum on the driving station of the scraper-chain conveyor between the two side walls of the frame, so that it can be removed to its open end without the conveyor drive having to be detached from the machine frame and removed--see DE-AS 17 56 355--. In this arrangement the chain drum has axially projecting coupling flat pins at both ends with which it can be inserted from the end of the frame through insertion slots arranged in the side walls into the bearing openings in the side walls. The drive side coupling flat pin can be inserted into a corresponding end face coupling transverse groove in a drive shaft of the conveyor drive mounted on the exterior of the side wall and secured by means of detachable half rings secured on the inside of the side wall of the frame. This construction is comparatively complex and expensive. On the disassembly of the chain drum the screwed-on bearing rings have to be loosened and removed which in typical mining operations is an awkward and lengthy process. Furthermore, the bearing openings in the side walls of the frame must be provided with insertion slots which tend to weaken the frame.
An objective of the invention is to provide a drive station for a scraper-chain conveyor, in particular for use in underground mining operations, that is not excessively expensive, and which is designed so that the work of assembling and disassembling the chain drum can be made easier without relatively heavy components with screw connections having to be loosened and removed from the machine frame.